Multiple drill



June 28, 1960 H. c. HEATH MULTIPLE DRILL 3 Sheets-Sheet 1 Filed July 23, 1957 R E V m HARRY C HEATH ATTORNEYS June 28, 1960 H. c. HEATH 2,942,850

MULTIPLE DRILL Filed July 23, 1957 3 Sheets-Sheet 2 f/G 4 INVENTOR. HARRY C. HEATH I 7,7 I l O G 0 ATTORNEKS w 9A1 n 5 M 7 $7 G 5 J 2 9 7 4 .lh 3 9 m m m z w m C \E I 7 4 I f m a a June 28, 1960 H. c. HEATH 2,942,350

MULTIPLE DRILL Filed July 23, 1957 3 Sheets-Sheet S INVENTOR. HARRY C. HE A 771 BY M wwmz A 7' TOPNEVS United States Patent Office MULTIPLE DRILL Harry C. Heath, Boise, Idaho, assignor to The McKee Company, a corporation of California Filed July 23, 1957, Ser. No. 673,616

'5 Claims. (Cl. 255-4.4)

This invention relates to rock drills and more particularly to a multiple drill for use in drilling relatively deep holes for water, oil or the like.

There are two main types of existing rock drills, the percussion type and the rotary type. Rotary type drills, in which the cutting teeth of the drill grind away the rock by a rotary or oscillating movement, find substantial use in the oil drilling industry. These drills are built in various sizes and are used predominently in deep well drilling. In use, these drills are conventionally operated from a prime mover located at the ground'level with a long steel bar transferring the rotary movement from a turntable at the surface of the earth to the drill at the bottom of the hole.

The teeth of rotary type drills generally project radially outwardly from the axis of rotation of the drill bit and must be relatively tough, and cannot be brittle, in order to withstand the bending stress applied thereto by rotation of the bit against the rock. It is therefore extremely difiicult to use hard, wear resisting material, such as tungsten carbide, in bits of this type since such material has been found to be too brittle to withstand this type of drilling action. As a consequence, it is usually necessary to use a tougher, less wear resistant material in'rotary cutting bits with the result that such bits must be frequently replaced when drilling through hard rock.

Percussion type drill bits, on the other hand, have the advantages of being able to use very hard, wear resistant teeth since the same are subjected only to impact in the drilling process. The cutting teeth of percussion type bits are conventionally made of a material such as tungsten carbide which has the ability to resist wear to a great degree and although brittle, will nevertheless stand up under the striking force .applied to the-bit.

It is not feasible, however, to attempt to use a single impact bit of a size required for large deep holes as commonly required in oil and other deep drilling operations. The striking force applied to a percussion type bit is usually transferred through a steel rod from thesurface of the earth. In deep hole drilling it is impractical-to attempt to transfer any sizeable force through a rod over several hundred feet long. A large size single percussion bit is also substantially less efiicient than bits of smaller sizes.

A percussion bit, in order to be etfective, must b rotated slightly between impacts so that the teeth will not continue to hit the rock in the same place. Transmission of this rotary motion over along distance into a deep hole is particularly difficult and usually results in ineflicient use of the drill.

It is therefore an object of this invention to provide a multiple percussion drill for deep 'well drilling.

It is anotherobject of this invention to provide a rock drill permitting the use of hard, wear resistant cutting bits.

Still another object of this invention is the provision of a drill for deep well drilling havingsubstantially lower powerrequirements than conventional a from line 44 of Fig. 3;

Patented June 28, g 1950 It is yet another object of this invention to provide improved means for operating a plurality of percussion type bits in a deep well drill.

A further object of this invention is the provision of a rock drill having a plurality of bit cutting edges and means for impacting said cutting edges against the rock being drilled and for varying the orientation of said cutting edges between impacts.

A still further object of this invention is the provision of an improved method of rock drilling.

Other objects and advantages will become apparent from the following description taken in connection with the accompanying drawings in which:

Figs. 1A and 1B are side elevational views of the rock drill of this invention.

Fig. 2 is an enlarged longitudinal sectional view of th upper portion of the drill of Fig. 1A;

Fig. 3 is an enlarged bottom plan view of the drill of Fig. 1B; v

Fig. 4 is an enlarged, longitudinal sectional view of the lower position of the drill of Fig. 1B as seen generally Fig. 5 is a cross sectional view as seen of Fig. 2;

Figs. 6A and 6B are longitudinal sectional views simi lar to the upper portion of Fig. 2, and showing some'of the parts thereabove;

Fig. 7 is a cross sectional view as seen from line 7-'7 of Fig. 6A;

Fig. 8 is a cross sectional view as seen from line 8 of Fig. 4;

Fig. 9 is a greatly enlarged side elevational view of one of the cutting bits of the drill of Fig. 1B, showing means for connecting the cutting bit to its operating means; and,

Fig. 10, is a semi-schematic view of the cutting bit operating hammers and associated valve control means.

In detail, referring to Figs. 1A and 1B, the drill of this invention comprises an elongated cylindrical body member generally, designated 1, having a hollow interior chamber which may be divided into a plurality of compartments 2, 3, 4, 5, 6, 7 and 8 by a plurality of dividers 9, 10, 11, 12, 13 and 14.. Body memberyl is closed at its opposite ends by caps 15, '16. This structure may, of course, take a variety of forms but body member 1 is preferably assembled from a plurality of tubular sections of pipe or the like stacked end to end with'the aforementioned dividers therebetween. In this manner each of from line 5 5 the compartments is formed by a tubular section and a' pair of dividers or a divider in one of the end caps.

Any suitable means may be used to hold the tubular sections and dividers and end caps together, such as long bolts extending through the stack or by threading each successive section or divider on to the preceding one. The body sections may also be shrunk fit together as shown. Whatever the specific method of assembling the drill body the result is an elongated cylindrical housing for the drill operating mechanism.

Each of the four lower compartments 5, 6, 7, 8 houses a drill actuating or hammer means 20, 21, 22, '23.. Each of said hammer means comprises a generally vertical cylinder 24 (Fig. 4) having an upper port 25, and a lower port 26 with a piston 27 being mounted in said cylinder for reciprocation between said ports. Projectingdownwardly from each piston 27 is a hammer 28 which is adapted to move in a generally vertical path with piston 27 for striking the upper end of a stiff rod 29 which extends into the end of cylinder 24 in the pathof travel of hammer 28. Each rod 29 extends downwardly from its associated cylinder and projects through. the lower end nector 30.

fluid flows from chamber 3 through openings 79, formed in divider 10, into chamber 4 for operating the hammer means in sequence as previously described.

The fluid used to operate the drill may be a mixture of water containing finely pulverized materials such as clay or bentonite or graphite, and is commonly referred to as drilling mud. This fluid is pumped through conduit 75 from the ground surface by conventional pump means and serves not only as an operating medium for the various fluid drive mechanisms described, but also as a flushing medium for carrying out the rock chips and other material cut by the drill.

At times it is found necessary to flush out the drill hole without operating the drill at the same time. For this purpose, conduit 75 is-formed, at its lower end adjacent drill body 1, from a pair of telescopically disposed pipe sections 104,105 (Figs; 6A, 6B). Lower section 104 is circular in cross section and may be flanged and bolted, as at 106, or otherwise secured to the stub of conduit 75 which is journalled in bearing 76 on drill body 1. Upper section 105 is square or noncircular in cross section and is secured tothe remainder of the conduit which extends to the surface of the ground.

The upper end of section 104 is provided with a bushing 107 secured thereto in which section 105 is slidably received. The lower end of section 105 has a collar 108 secured thereto, which collar is slidably received insec- [lOBi104. A f

In the position shown in Fig. .6B sections 105, v104 merely convey fluid to the inside of drill body 1, as explained. The lower end of section 105 and the upper end of section 104 are, however, respectively provided with ports 109,110, which register with one another when section 105 is lifted to bring collar 108 into engagement with bushing 107. When the sections are in this position the fluid in conduit 75 may escape through ports 109, 110 to the outside of the drill body 1 for flushing out the drill hole.

The normal spacing between collar 108 and bushing 107, perhaps 20 to 30 feet in Fig. 6B, also permits jarring the drill bit loose in the event itbecomes stuck. By rapidly liftingsection 105 to impact collar 108 with bushing 107 an upward shock may be transmitted through section 104 to the drill body 1.to break the latter loose from a rock formation in which it may become stuck. Bushing 107 and collar 108 thereby act as stop means limiting the axial movement of sections 104, 105.

It will also be noted that the weight of the pipe or conduit above section 105 may be supported on the draw works at the surface and 'need not rest on the drill body or bits, thereby facilitating the drilling operation. In this connection, as drilling progresses section 104 will follow the drill body'down the hole until the ports 109, 110 register. At this time the fluid pressure will drop off from that required to operate the drill, and the operator, noting this at the surface may then lower the con duit and section 105 to the position of Fig. 6B to continue drilling.

As previously described, the lower end of drill body 1 is closed by a cap 16 through which drill rods 29 project. In order to facilitate assembling the drill of this invention, cap 16 is preferably formed in three sections 82, 83, 84 (Fig. 3) which are sectors of the complete disc. Sectors 82, 83, 84 adjoin each other at the openings through which the rods 29 of the bits 31 project through the cap 16 and said sectors may be joined together by any suitable means.

Since it is necessary that the bits 31 be capable of a limited vertical movement it would not be practical to rest the entire weight of the drill on the cutting bits.

Therefore cap 16 is provided with a plurality of supporting means, generally designated 85 (Fig. 4) which project downwardly from cap 16. Means 85 comprise an open ended socket 86 which supports a large ball bearing 87 so the same may rest on the bottom of the hole being drilled.

Socket'86 may be secured to the drill body 1 by means of threaded bolts 88 extending through cap 16 and in threaded engagement with a lug 89 secured to the inner wall of body 1. Each of bolts 88 and lugs 89 may also facilitate securing the sectors 82, 83, 84 in place on the drill body. The supporting means are arranged interspaced with the drill bits so as to provide suflicient support for the drill rotating on the bottom of the hole. In the specific form shown, three ball bearing supporting means 85 are arranged equally spaced between the outer ring of drill bits 31.

Bits 31 may be'of a conventional percussion type providing a threaded socket 92 (Fig. 9) for receiving the threaded end 93 of the bit connector 30 provided at the end of each drill rod 29. Each bit 30 is provided with a plurality of cutting edges 94 (Figs. 3, 9) which are directed axially of the drill rods 29. Edges 94 may be arranged in a shape similar. to the star shown in which said edges radiate from the center of the bit. As seen in Fig. 9, the cutting edges are formed similar to wide angle chisel edges. It will also be noted that the outer end ot'the bit carrying the cutting edges is flared wider than the body of thebit carrying socket 92. This facilitates the extension of a portion of the outer ring of cutting bits radially outwardly of body 1, as previously described.

In order to prevent bits 31 from becoming accidentally disconnected from drill rods'29 the opposed shoulders 95, 96' of the bit connector, 30 andbit 31, respectively, surrounding socket 92 and threads 93, may be provided with V notches 97 for receiving the dogs 98 on a pair of washers 99, 100 interposed between .said shoulders. In efiect, the notches 97 provide a plurality of shoulders which are engageable by dogs 98 to prevent rotation of washers 99, and 100 in one direction with respect to' shoulders 95, 96.. Forming notches 97 and dogs 98 inv opposite direction as shown in Fig. 9 prevents rotation between washer 99. and shoulder and between washer and shoulder 96 in a direction to unthread bit 31 from connector 30. The washers 99 and 100 may then be spot welded, as at 101, around their outer edges so as to prevent rotation between said washers.

In this manner a simple locking device is provided for preventing the unscrewing of bits 31 from the drill rods 29. When it is desired to replace bits31 the welds 101 may be ground off permitting relative rotation between washers 99, 101 and removal of the bit from drill rod.

In order to prevent each of the bits 31 in the outer ring (Fig. 3) from striking in the same position as that of the preceding bit, said bits are preferably orientedat diflferent degrees with respect to a diameter of drill body' 1. This may be easily done by positioning the bits with cutting edges 94 of each bit from a different angle with a diameterof body 1 through the center of the bit. In order to so orient the bit, shims or thin washers may be sandwiched between the dog washers 99, 100 providing for a lesser or greater degree of threaded movement be tween the bit 31 and connector 30.

In operation the drill body 1 is lowered on the end of conduit 75 into the hole. Body '1 rests on the bottom of the hole onball bearing support means 85, and further lowering conduit 75 to the position shown in Fig. 6B initiates the flow of operating fluid into chamber 2 and thence through the drill body to operate motor 62 for rotating said body at relatively slow speed. A speed of 12 to 60 revolutions per minute of drill body 1 about the aXis'of conduit 75 has been found satisfactory.

Fluid motor 58 causes rotation of gate member 50 in control valve 39 so as to initiate striking action of the hammer means 20, 21, 22, 23 in sequence thereby impacting each of the bits 31 alternately with the others. This sequential impacting of each of the bits plus the rotation of drill body 1 to change the position of the bits between impacts causes fracturing of the rock in a circular path. Since the drill bits 31 project radially outwardly of the body 1 the hole drilled by said bitsis sufa, ficiently'large to permit the body 1 to follow down the hole. Space is also provided for the return of the fluid through openings 102 (Fig. 3) in the bottom cap 16 outwardly between the bits to carry away the cuttings and rock ships up the outer side of drill body 1 and back to the surface.

With the drill of this invention the cutting edges 940i the percussion type of drill bits 31 may be made of an extremely hard wear-resisting material such as tungsten carbide. No appreciable bending or shearing stress is applied to the drill bits which would tend to fracture such brittle material. The major force applied to the drill bits is an impact force directly against the cutting edges which is easily withstood by such a wear-resistent material. Therefore, the drill bits may be used for a considerable period of time before sufiicient wear, is incurred to necessitate replacement. V

The drill of this invention may be made in any desired size using any number of a plurality of drill bits; in a variety of arrangements,

Although the invention has been described and illustrated" in'detail, such is 'not to be taken as restrictive thereof since it is obvious that modifications could be f1; 'A rock drill comprising: an elongated cylindrical J body, having closed ends and a hollow chamber between saidends'a 'fluid conduit connected to said body and provided with'apertures communicating with said chamher, means connected to said conduit and said body for rotating. said body, a plurality of fluid operated, reciprocable hammers mounted in said chamber and each having its own path of'travel, means for operating said hammers in sequence, a stiff rodprojectin'g'from a position in'the path of travel of each of said hammers through the other end of said body and terminating in a bit connector, and a cutting bit secured to each of said rods at said connector, each of said bits having a plurality of cut- 'ting; edges directed axially of said rod and radiating from.

a central point of said bit.

2. A rock drill comprising: an elongated cylindrical 7 body having closed ends and a hollow chamber betweensaid ends, a coaxial hearing at one end of said body open- .ing into saidchamber, a fluid conduit received in said bearing and provided with apertures communicating with said chambena fluid motor in said chamber connected to said conduit and said body for rotating said body, a-plurality of fluid operated, reciprocable hammers mounted;

in said chamber and each having its own path of travel,

1 'rneans for operating said hammers in sequence, a stiff rod 7 projecting from a'position in the path of travel of each oi'said hammers through the other end of, said body and terminating in a' bit connector; and :a. cutting: bit secured to each of said rods at said connector,- each of' said bits. 7 having a plurality of cutting edges directed axially of said in said bearing and provided with apertures communicating with said chamber, a 'iiuid motor in said chamber connected 'to said conduit and said body for rotating said body, a plurality of fiuid operated, reciprocable hammers mounted in said chamber and each' having its own path of travel, means for operating said hammers in sequence,

pwith said chamber, a fluid motor in said chamber. con

a stiffrod projecting from a position in the path of travel of each of said hammers through theother end of said body and terminating in a bit connector, and cutting bit secured to each of saidrods at said connector, each of said bits having a plurality of cutting edges directed axially of said rod and radiating from a central point on said bit, said bits being arranged so that the orientation of the cutting edges of each bit with respect to a diameter of said body varies from the others of said bits.

4. A rock drill comprising: an elongated cylindrical body having closed ends and a hollow chamber between said ends, a coaxial bearing at one end of said body opening into said chamber, a fluid conduit received in said bearing and provided with apertures communicating with said chamber, a fluid motor in said chamberconnected to said conduit and said body for rotating said body, a plurality of fluid operated, reciprocable hammers mounted in said chamber and each having its own path of travel, means for operating said hammers in sequence, a stiff rod projecting from a position in the path of travel of each of said hammers through the other end of said body and terminating in a'bit connector, a cutting bit secured to each of "said rods at said connector, each of said bits having a plurality of cutting edges directed axially of said rod and radiating from a central point on said bit, said operating means including a multiple' valve mounted in said chamber and having a plurality of ports each connected to one of s'aid'hammers, 3O

and a moveable gate member adapted to openi and. close said ports in'sequence, and motor means'connected to said gate member for moving the same.

5. A rock drill comprising: an elongated cylindrical body having closed ends anda hollowchamber between said ends, a coaxial heating at one end of said body opening into said chamber, a fluid'conduit' received in said bearing and provided'with apertures communicating nected to said conduit and saidbody for rotating said body, a plurality of fluid: operated'reciprocable ham- 'r'ners mounted in said chamber and each having its own path, of travel, means for operating said hammers in 7 sequence, a stiff rod projecting froma position in the path of travel. of each of said hammers through the other end of said body and terminatihglin a bit connector, a'

cutting bit secured'to each of said rods at said connector,

each of said bits having .a-plurality of cutting edges di-' rected axially-of said rod and radiating from a'central point on said bit, said conduit including a pair of telescopically disposed sections axially'slidable with respect to each other and each provided with-ports opening outwardly therethrough and registering with each other in one axial position, stop means-on said sections engage able with each other for limitinglaxialmovement of said sections in one direction to's'aid 'one position and sup porting feet projecting from'said other end of said body for supporting said body'on' the'bottom of the drill hole.

in a position to allow limited axial movement of said bits. 7 7

References Cited in the file of this patent V UNITED STATES PATENTS 559,514 Collins May 5, 1 9 1,287,477 Simpson Dec. 10, 1918 2,052,019 Baker Aug. 25,1936 2,241,712 McNamara May 13, 1941 2,367,319 Wahlberg Jan; 16, 1945 2,490,853 Stilley May 21, 1946 2,672,847 Bergmann Mar. 23,- 1954 2,765,146 Williams Oct.' 2, 1956 2,896,916' Clavier et al. July 28, '1959 

